Loop-spreader fob sewing-machines



0. L. LAWSON & J. H. REED. LOOP SPREADER FOR SEWING M'ACHINES.

APPLICATION FILED MAR. 24. 1915.

Patent-ed Aug. 15, 1916.

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OSCAR L. LAWSON AND JAMES H. REED, OF LYNN, MASSACHUSETTS.

LOOP-SPREADER FOR SEWING-MACHINES.

Application filed March 24, 1915.

To all whom it may concern:

Be it known that we, OSCAR L. LAWSON, a subject of the King of Sweden, and JAMES H. REED, a citizen of the United States, residing at Lynn, county of Essex, and State of Massachusetts, have. invented a certain new and useful Improvement in Loop- Spreaders for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

In the prior application of Oscar L. Lawson filed March 25, 1915, Ser. No. 17,0 17 there is shown a shoe sewing machine having various stitch forming instrumentalities and a loop spreader by means of which one side of the loop is drawn laterally away from the other side of the loop to permit the hook of the shuttle to pass into the loop. In the device shown in said prior application the spreader has only a lateral movement as viewed from the front of the machine and depends for engagement with the loop upon the fact that the loop is carried backward somewhat because the needle moves in the arc of a circle.

The present invention has for its object to provide a loop spreader which shall have a more positive and satisfactory movement, and which shall not depend upon the backward movement of the thread produced by movement of the needle in the arc of a circle to cause it to enter the space between the two sides of the loop. To this end we have provided means by which the spreader is not only moved sidewise but is also periodically pushed forward to enter the loop.

The invention will be fully understood by reference to the following specification, taken in connection with the accompanying drawings, and the novel features thereof are pointed out and clearly defined in the claims at the close of this specification.

In the drawings, Figure 1 is a side elevation of a portion of the machine embodying the invention. Fig. 2 is a front elevation of the parts shown in Fig. 1 with the exception of the drive. Fig. 3 shows the loop spreader pushed forward into the loop. Fig. 41 is a front elevation showing the parts in the position occupied at the time when the side of the loop has been moved laterally. Fig. 5 is a top plan view showing the spreader and needle holder.

Referring to the drawings, there is shown at 11 the shuttle shaft, at 12 the needle shaft,

Specification of Letters Patent.

Patented Aug. 15, 1916.

Serial No. 16,766.

1 1 is provided with a spiral gear 15 meshing with a spiral gear 16 on a shaft 17. The

shaft 17 is providedat its other end with a spiral gear 18 engaging a corresponding spiral gear 12 indicated in dotted lines in F 1g. 1. 1t w1ll thus be seen that the cam shaft 13 is caused to revolve by the main shaft 14: and in time with it.

At 20 is shown the needle, at 21 the presser foot, at 22 the work support, and at 23 the needle guide. The shuttle is designated 24, its point or hook being marked a. The awl is designated 25. 20 descends through the hole in the work formed by the awl 25, the thread is laid in the hook of the needle by instrumentalities not necessary to be referred to and the needle rises to the position shown in Figs. 1, 3 and 4:. It is then necessary to have the sides of the loop spread apart or separated to enable the hook a of the shuttle 24L to pass into the loop. To this end, we provide a spreader 26 shown in plan in Fig. 5. It consists of a pointed member bent slightly at the end to engage the thread more securely. The spreader 26 is mounted on the upper end of a vertical rock shaft 27 which is itself mounted in a block 28. The lower end of the rock shaft is provided with an arm 29 on which is a cam roll 30; said cam roll 30 is in a groove 41 in the cylindrical surface of a cam 31 mounted on the cam shaft 13. It will therefore be seen that as the cam shaft is revolved in time with the various stitch forming instrumentalities the rock shaft 27 is moved and the point of the spreader is oscillated sidewise to spread the loop laterally.

For the purpose of causing the spreader to be pushed forward into the loop, we mount the block 28 in which the rock shaft 27 is carried on a rod 32 slidable in the frame 33. The rear end of the rod 32 is pivoted on the upper end of a swinging cam lever 38 pivoted at its lower end to a fixed part of the machine as indicated at 34.

At 35 is shown a cam roll engaging a groove 36 in the face of a cam 40 on the shaft 13. It will therefore be seen that as the cam shaft 13 revolves, the point of the spreader is pushed forward well into the loop so that when the swinging movement When the needle of the spreader takes place there is no danger of the thread becoming disengaged from the spreader. The forward movement of the block 28 in which is mounted the rock shaft 27 is not suflicient to displace the cam roll 30 or afl ect substantially the lateral movement of the spreader produced thereby. The two cams on the shaft 13 are so placed with regard to each other that the sideWise movement takes place immediately after the end of the spreader has been pushed forward into the loop. These movements are also properly timed with relation to the movement of the needle and shuttle.

What we claim is:

1. In combination with stitch forming instrumentalities a loop spreader comprising a member forming one arm of a rock shaft, means for oscillating the spreader on the rock shaft and means for pushing the rock shaft forward bodily to cause the point of the spreader to enter the loop.

2. In combination with stitch forming instrumentalities, a rock shaft, one arm of which comprises a pointed member for engagement with the loop, and the other arm of which is provided with a cam follower, a cam to move said cam follower, a slidable member in which said rock shaft is mounted, and a cam to slide said member.

In testimony whereof we affix our signatures, in presence of two Witnesses.

OSCAR L. LAWSON. JAMES H. REED.

Witnesses:

GEORGE P. DIKE, ALICE H. MORRISON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. C. 

